This invention relates to an electric motor vehicle using a motor as a drive motive power, and particularly to an electric motor vehicle which is preferably applied to two wheelers and three wheelers such as motorcycles and scooters.
It is now said to be an age of electric motor vehicles. It is said that the electric motor vehicles will solve most of the environmental issues such as the exhaust gas from automobiles which is said to make up about 70% of air pollution, noises, or the like, and will extend the life of oil resources by two times or more.
Known electric motor vehicles are provided as their drive system with a battery, a motor, and a controller for controlling the speed of the motor, and a wheel is rotated by a drive transmission mechanism like conventional automobiles, or a wheel is rotated by a motor disposed on it without necessitating such a drive transmission mechanism like conventional automobiles. And, in developing an electric motor vehicle, the improvement of the performance of an onboard battery is an issue to be solved and it will not be long before it is solved.
Incidentally, the electric motor vehicle is also demanded to have its safety improved together with the improvement of its performance. A mere replacement of the drive motive power of a conventional gasoline automobile by a motor can not sufficiently provide the safety of the electric motor vehicle. Specifically, the electric motor vehicle uses electricity for a drive source, and the power is a motor which rotates at a high speed as compared with an engine. Therefore, a trouble of the electric system or a failure of the motor may suddenly stop a running vehicle or suddenly start a vehicle which was out of action. Besides, in common to a running vehicle and a stopping vehicle, there is the possibility that a driver or a mechanic may suffer from an electric shock, be caught by the drive unit in the vicinity of the motor, or break the motor or the controller when servicing. These troubles or the necessity of protection is caused due to the device or structure peculiar in the electric motor vehicle, which is not seen in conventional automobiles.
The inventors involved in the development of an electric motor vehicle have proposed the following points to prevent accidents or failures from occurring and to assure safety.
First point for safety: To avoid a travel motion trouble of the electric motor vehicle which may suddenly occur when traveling, for example, a sudden stop of the electric motor vehicle.
When the vehicle is exposed to wind and rain and suffers from vibration when traveling, water may enter the motor or the electric control circuit, causing an insulation failure (electrical short). This is very dangerous because it leads to a stop of the electrical motor vehicle. In this connection, the improvement of a stator fixing structure, a motor case structure, and a waterproof structure of electronic equipment will be proposed. And, the vibration during traveling loosens individual sections or causes component parts to come off, resulting in stopping the motor or lowering the efficiency of the drive transmission mechanism. This will cause the electric motor vehicle to stop. In this connection, the improvement of a stator fixing structure, an attaching structure of a fixed substrate of a magnetic detecting element, a buildup structure of a power transmission mechanism, a switch structure, and a fixing structure of an encoder magnet will be proposed.
Second point for safety: To prevent a sudden start of the electronic motor vehicle which may happen suddenly.
Since the motor has a rapid start-up of rotation and a high torque at a low speed, the electric motor vehicle may start suddenly depending on a way of driving operation. This is very dangerous. On this point, the improvement of a drive controller will be proposed.
Third point for safety: To avoid a danger when inspecting the electric motor vehicle.
In view of preventing an electric shock, the improvement of a power circuit and a stator winding will be proposed.
Fourth point for safety: To protect the controller and the drive unit of the electric motor vehicle.
Overheating of the motor may result in its breakdown. On this point, a protection device will be proposed. Since this protection device prevents a breakdown of the motor from happening and also prevents a sudden stop of the vehicle due to the motor failure, it also relates to the above first point for safety. And, in view of preventing destruction of the device due to malfunction, the improvement of a protection device and a structure for protecting the drive unit in packaging, transporting and assembling works will be proposed.
The above first to fourth points for safety are not sufficient if any of them is alternatively disposed on the electric motor vehicle but all of them shall be preferably disposed on the electric motor vehicle. And, the above first to seventeenth inventions relate to the drive system of the electric motor vehicle and also to at least any of the above first to fourth points for safety, and some of them relate to more than one of the above points. Specifically, the above first to seventeenth inventions of this application are closely related to one another for securing safety. They will be described hereinafter in detail to clarify the contents of this application which aims to obtain an electric motor vehicle having high safety.